Summary

All I can do now is offer a short summary and some hints to aid you on your quest:

• As Einstein said: make it as simple as possible, but not simpler.
• Meaning to create the language as close to the game but also as comfortable to the player as you can, while not generalizing things too much ( eg by putting buildings and units into the same build-list ).
• Use real life as a basic model to give players familiarity.
• Allow players to express their individuality by allowing UI refinements using shortcuts ( to spells in Baldur's Gate) and/or basic UI elements that can be freely used ( UO).
• Differentiate the controls. This gives the players a "feeling" of your world.
• Place things belonging together closer to each other.
• Reduce the time/distance to frequently used objects and give them proper sizes ( this also decreases time and does not distract the player too much with fine tuning his mouse movements)
• Do not tear the player completely away from the game with fullscreen interfaces ( especially in real time games!), since he loses complete control over the actions and will always be hectic to leave the menu again.

Conclusion

Well, these are at least some rules, but this merely scratches the surface into which it is best to dive on your own!

I hope you enjoyed this article a bit and are interested in reading Part II, in which I'll cover the Game to Player mapping of game outputs. Defining what data is needed and how it should best be converted. Hope you'll be with me then!

- Martin Kremecek